Electroluminescent-photocell readout devices



June 20, 1967 I 1v, RYCHLEWSKI ELECTROLUMINESCENT-PHOTOCELL READOUT DEVICES 3 heets-Sheet 1 Filed Aug. 28, 1963 INVENTOR Thaddeus M Ryc/l/euski QM r/W ATTORNEY June 20, 1967 T. v. RYCHLEWSKI 3,3

ELECTROLUMINESCENTPPHOTOCELL READOUT DEVICES Filed Aug. 28, 1965 3 Sheets-Sheet 2 .SIGNAL OUTPUT INVENTOR Thaddeus M @yc/z/eWs/n' ATTORNEY June 1967 "r. v. RYCHLEWSK! 9 2 323 ELECTROLUMINESCENT-PHOTOCELL READOUT DEVICES Filed Aug. 28, 1963 3 Sheets-$heet 5 INVENTOR Thaddeus 1 Fj/ch/eWs/(i ATTORNEY United States ?atent O 3,327,123 ELECTROLUMINESCENT-PHOTOCELL READOUT DEVICES Thaddeus V. Rychlewski, Seneca Fails, N.Y., assignor to Sylvania Electric Products linc., a corporation of Delaware Filed Aug. 28, 1963, Ser. No. 305,175 2 Claims. (Cl. 250-419) This invention relates to a card readout mechanism utilizing photoconductive elements and to a process for making such elements. The readout device may be utilized in computing and statistical machines. More specifically, this invention relates to a device for sensing the presence of perforations in a record card or strip and translating them into electrical pulses, the conversion being effected by circuitry involving the use of electroluminescent devices and photocells.

It is an object of the invention to make a simple device of this character with parts which can be easily manufactured.

It is a further object of the invention to associate a memory device with a perforated card or perforated strip reader of the above character.

Another object of the invention is to provide a process of making photoconductive elements for use in readout devices which is easier and less expensive to use than those used heretofore.

For a better understanding of the present invention, together with other and further objects, advantages, and capabilities thereof, reference is made to the following disclosure and appended claims in connection with the accompanying drawings in which:

FIG. 1 is a schematic exploded view of the readout device and associated memory device;

FIG. 2 is a cross-sectional view of a single pair of associated readout and memory devices and associated parts;

FIG. 3 is a circuit diagram explanatory of the electrical action which takes place in the devices of FIG. 2;

FIG. 4 is a perspective view of a rod coated with electroconductive and photoconductive material utilized in the readout device; and

FIG. 5 is a transverse section through the coated rod illustrating a step in the manufacture of the rod.

Referring to the drawings in greater detail, at 8 in FIG. 4 is indicated generally a photoconductive element comprising a transparent rod 10 of Pyrex Or like high melting point insulating transparent material having opposed fiat faces 12 and 14 covered with photosensitive resistance material 15, 15a respectively, preferably of a nonlinear electrical characteristic, so that when illuminated the photosensitive material becomes sharply more conductive than when nonilluminated. Electrically connecting the photosensitive surfaces are spaced bands or partial rings of conductors 16, these providing the insulating spaces 18 between the conductive bands.

These photoconductive elements may be made by completely coating a cylindrical rod with a conductive paint, as of gold, by any known process such as dipping the rod in a suitable melt or dispersion of the gold, or by sputtering the gold on the rod or by evaporating the gold thereon. The rod may then be placed in a lathe and rotated while selected spaced areas of the rod are subjected to an abrasive wheel or abrasive slurry applied to the rod by a friction pad, or the coating may be cut to leave circular rings 16 of conductive material on the rod by the use of spaced knives arranged longitudinally of the rod. The rod may then have opposed diametrical portions 12 and 14 of it shaved or ground oif to form fiat surfaces. Next, a thin transparent photosensitive coating as of zinc su1- phide activated by copper (ZnS: Cu, with copper forming about three-tenths of one percent by weight of the mixture), may be applied to each of the flat surfaces so that electrical contact is made with all of the arcuate conductive ring sections on the rod.

The photosensitive material may be applied to the rod in any known manner as by brushing the coating onto the rod. Another method of application of the coating to the rod, as shown in FIG. 5, is to present the flat face to be covered with photoconductive material to a slot in a mask 17. The slot exposes the area of flat face between the ends of the arcuate conductive ring sections and a small area at the ends of the sections, and then the exposed area is sprayed. The resultant product is shown in crosssection in FIG. 5, wherein it will be noted the photoconductive material 15 or 15a slightly overlaps the ends of the arcuate section of rings 16. The coated rod is then placed in an oven to sinter the photosensitive material. .The photosensitive material may then have a protective coating of transparent wax applied thereto.

One end of the rod is provided with a conical recess 20 (see FIG. 1) to receive an end of an adjusting screw to be described and the opposite end of the rod is provided with a cylindrical recess (not shown) to receive the end of a spring, also to be described. A photoconductive element 8 such as just described is placed beneath a perforated wall, the openings in the wall being spaced apart to correspond with the possible spacings of the perforations in a record card or strip. Conveniently, and in order to maintain the rod light tight in areas other than that intended to be exposed to the openings in the plate, the rod is placed within an opaque insulative box, indicated as a whole at 22. For convenience in the manufacture and assembling of parts, the box may be comprised of a top section 24 perforated as indicated at 26, a bottom section 28, a front end plate 30, and a rear end plate 32. The rear end plate is fastened to a framework not shown and mounts in any convenient fashion, as by a stud, a helical cylindrical spring 34. The cylindrical recess in the rod, previously described, forms a seat for the free end of the spring. The front plate 30 has a central tapped opening 35 therethrough mounting an adjusting thumb screw 36 having a conical end which engages the conical recess 20 in the adjacent end of the rod. By rotation of the screw 36, the rod can be shifted longitudinally against the force exerted by spring 34 to properly align the conductive sections 16 with the perforations 26. Screws 38 pass freely through the end plates and are threaded into openings in the top and bottom sections of the box to hold all parts in assembled relationship. A gasket, as indicated at 40, may be used to prevent unwanted light leakage into the box.

To expedite reading out a card or strip, boxes may be grouped side by side, and to facilitate lining up of the boxes, each of the sections of the box may be equipped with studs 42 fitting into corresponding recesses 44 in an adjacent box. One of the end plates, as plate 30, has an electrical connection 46 extending therethrough making contact with a spring contact bar 47 running longitudinally of one of the top or bottom halves of the box. This bar, on one side of the rod, makes contact with all of the arcuate conductive sections 16. However, on the opposite side of the bar individual contacts are made with each of the conductive ring sections. For this purpose the lower box section 28 is provided with a number of contacts 43, as of rubber with conductive material therein to render the elements 48 conductive, one for each ring section on that side of the box. Thus if light, as from an elongated lamp 50, under control of perforations 52 in a card 54, passes through an opening 26 and impinges on photosensitive material 15, the material immediately in line with the light would become conductive and con duct current from the input voltage source 56 to that ring portion 16 which is nearest the irradiated photoco-n ductive section. Thence the potential would be applied via the associated contact or connector 48 to a transparent conductive strip 58 forming one of many such electrodes of an electroluminescent lamp 60 comprised of a large number of these strips 58, one for each conductor 48, an electroluminescent layer of material 62, a lower transparent conductive surface 64 covering the entire face of the laminate, and a glass substrate 66. The surface 64 is connected to the remaining pole of the source of input voltage.

The box 22 has openings 68 in the bottom half 28 thereof corresponding in size and position to the openings 26. When the lamp 60 becomes illuminated in a particular area, the photosensitive material 1511 on the rod opposite the illuminated opening 68 will become conductive, thus establishing a shunt circuit to the strip 58 from the voltage source, the current flowing via strip 47, contacting ring section 16, photoconductive material a, and contact 48 to the strip 53. Thus the lamp 60 at the energized conductor strip 58 will remain energized regardless of the obturation of the opening 26 by the shifting of the card 54 or the extinguishing of the light 50. The illumination will persist until the circuit from source 56 is broken, as by opening of a switch 69 in series in the line to strip 47.

The illuminated sections of the lamp 60 also illuminate sections of photoconductive areas on a second rod 70 similar to rod 10 except that there is no photoconductive material on the lower surface of the rod. On the upper fiat surface of the rod there is photoconductive material 72 opposite openings 74 in the upper half of a box 76 which is like box 22 except that the lower half is imperforate and the end wall 78 has no lead in contact member equivalent to the member 46. There are as many boxes 76 as there are boxes 22, the number depending on the number of columns of perforations in a card or strip 54, The bottom half of each box 76 has signal input leads or connectors 80 and signal output leads or connectors 82 of the same kind of material as the connectors 48, each pair of leads 80 and 82 contacting an opposite pair of the ring sections 16 on the rod 70. When any localized area of the photoconductor 72 is illuminated, a corresponding pair of leads 80 and 82 will be in electrical connection with each other for signal transmission via an individual line 84 to a recording or indicating medium. For convenience in manufacture, both rods 10 and 70 are essentially the same insofar as the ring sections 16 are concerned. However, if all the ring sections 16 on the right-hand side of the rod in FIG. 2 were joined, then only one signal output connector 82 would be needed. In that event each of the connectors 80 would be provided with separate switches leading to the signal input source, and a spiral cam or cams fixed on a rotating shaft, oneshaft and cams for each casing 76, would close the separate switches seriatim, to pulse out the signals on the single signal output line 84, from each casing. Also in that event, both rods 10 and '70, after being coated with its conductive coat of gold or the like, need have only half of the cylindrical surface treated to remove portions of the coating.

After each readout operation via the rod 70, the machine cycle will extinguish the light 50 and open the switch 69, thus extinguishing all the excited portions of the lamp 60; and a new card 56 or section of strip could replace the old. Thereupon the lamp 50 would again be lit and the new readings on the card or strip could then be read off on the line or lines 84. Obviously the extinguishing of the light 50 and opening of the switch 69 could be effected by hand.

Any suitable framework and brackets may be employed to properly support the lights 50 above the boxes 22.

Likewise, guide for the card 54 or strip, the underlying electrolumlnescent lamp, and the underlying box 76 or boxes could be provided with brackets supporting the same on the framework. Since these parts are not specifically of importance, they have not been illustrated.

While there has been shown and described what is at present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention as defined by the appended claims.

What is claimed is:

1. In a readout device, a box, an insulative rod sup ported in said box, said rod having upper and lower photoconductive surfaces, a source of light above said box, perforations in the upper and lower walls of said box, and conductive ring sections on the rod to connect the photoconductive section on the upper surface of the rod and adjacent one of the perforations to a photoconductive section on the lower surface of the rod which is opposite a perforation in the lower wall of the box, means to apply a potential to the photoconductive material, on both surfaces of the rod, throughout the length of the rod; connectors on one side of the rod, one for each conductive ring section, an electroluminescent lamp comprised of a conductive coating forming an electrode, electroluminescent material on the top surface of the coating, and transparent isolated conductors on the top surface of the electroluminescent material, each isolated conductor being opposite an associated perforation in the bottom of the box, whereby when a top area of photoconductive material is illuminated, the electroluminescent material will be illuminated, irradiating the lower photoconductive ma terial and establishing a shunt circuit for the electroluminescent material, said electroluminescent material remaining lit notwithstanding any failure to continue illuminating the upper photoconductive surface of the rod, a lower box located below the electroluminescent lamp having openings in the upper wall in line with isolated conductors of the electroluminescent lamp, a second insulative rod in said lower box, having its upper surface coated with a photoconductive material, and conducting ring sections spaced along the length of the rod, on the sides of the rod, each ring section contacting the photoconductive material at the top of the second rod and nonconnected to other ring sections at the bottom of the rod, signal input connectors, one for each ring section v on one side of the rod, contacting the ring sections on that side of the rod, and signal output connectors simi-' larly contacting the ring sections on the opposite side of the second rod.

2. In a readout device, a box, an insulative rod supported in said box, said rod having upper and lower photoconductive surfaces, a source of light above said box, perforations in the upper and lower walls of said box, and conductive ring sections on the rod to connect the photoconductive surface on the upper part of the rod and adjacent one of the perforations to a photoconductive surface on the lower part of the rod which is opposite a perforation in the lower wall of the box, a means to apply potential to the photoconductive material on both sur-- faces of the rod, throughout the length of the rod, connectors on one side of the rod, one for each conductive ring section, an electroluminescent lamp comprised of a trans.- parent conductive coating forming an electrode, electroluminescent material on the top surface of the coating, and transparent isolated conductors on the top surface of the electroluminescent material, each isolated conductor being opposite an associated perforation in the bottom of the box, whereby when a top area of photoconductive material is illuminated, irradiating the lower photoconductive material and establishing a shunt circuit for the electroluminescent material, said electroluminescent material remaining lit notwithstanding any failure to continue illuminating the upper photoconductive surface of the rod, a lower box located below the electroluminescent lamp having openings in the upper wall in line with the isolated conductors of the electroluminescent lamp, a second insulative rod in said lower bo-X having its upper surface coated with a photoconductive material, and conducting ring sections spaced along the length of rod, on the sides of the rod, each ring section contacting the photoconductive material at the top of the second rod and nonconnected to other ring sections at the bottom of the rod, signal input connectors, one for each ring section, on one side of the second rod contacting the ring sections on that side of the rod, and signal output connectors similarly contacting the ring sections on the opposite side of the second rod.

References Cited UNITED STATES PATENTS RALPH G. NILSON, Primary Examiner.

I. D. WALL, Assistant Examiner. 

1. IN A READOUT DEVICE, A BOX, AN INSULATIVE ROD SUPPORTED IN SAID BOX, SAID ROD HAVING UPPER AND LOWER PHOTOCONDUCTIVE SURFACE, A SOURCE OF LIGHT ABOVE SAID BOX, PERFORATIONS IN THE UPPER AND LOWER WALLS OF SAID BOX, AND CONDUCTIVE RING SECTIONS ON THE ROD TO CONNECT THE PHOTOCONDUCTIVE SECTION OF THE UPPER SURFACE OF THE ROD AND ADJACENT ONE OF THE PERFORATIONS TO A PHOTOCONDUCTIVE SECTION ON THE LOWER SURFACE OF THE ROD WHICH IS OPPOSITE A PERFORATION IN THE LOWER WALL OF THE BOX, MEANS TO APPLY A POTENTIAL TO THE PHOTOCONDUCTIVE MATERIAL, ON BOTH SURFACES OF THE ROD, THROUGHOUT THE LENGTH OF THE ROD; CONNECTORS ON ONE SIDE OF THE ROD, ONE FOR EACH CONDUCTIVE RING SECTION, AN ELECTROLUMINESCENT LAMP COMPRISED OF A CONDUCTIVE COATING FORMING AN ELECTRODE, ELECTROLUMINESCENT MATERIAL ON THE TOP SURFACE OFF THE COATING, AND TRANSPARENT ISOLATED CONDUCTORS ON THE TOP SURFACE OF THE ELECTROLUMINESCENT MATERIAL, EACH ISOLATED CONDUCTOR BEING OPPOSITE AN ASSOCIATED PERFORATION IN THE BOTTOM OF THE BOX, WHEREBY WHEN A TOP AREA OF PHOTOCONDUCTIVE MATERIAL IS ILLUMINATED, THE ELECTROLUMINESCENT MATERIAL WILL BE ILLUMINATED, IRRADIATING THE LOWER PHOTOCONDUCTIVE MATERIAL AND ESTABLISHING A SHUNT CIRCUIT FOR THE ELECTROLUMINESCENT MATERIAL, SAID ELECTROLUMINESCENT MATERIAL REMAINING LIT NOTWITHSTANDING ANY FAILURE TO CONTINUE ILLUMINATING THE UPPER PHOTOCONDUCTIVE SURFACE OF THE ROD, A LOWER BOX LOCATED BELOW THE ELECTROLUMINESCENT LAMP HAVING OPENINGS IN THE UPPER WALL IN LINE WITH ISOLATED CONDUCTORS OF THE ELECTROLUMINESCENT LAMP, A SECOND INSULATIVE ROD IN SAID LOWER BOX, HAVING ITS UPPER SURFACE COATED WITH A PHOTOCONDUCTIVE MATERIAL, AND CONDUCTING RINGS SECTIONS SPACED ALONG THE LENGTH OF THE ROD, ON THE SIDES OF THE ROD, EACH RING SECTION CONTACTING THE PHOTOCONDUCTIVE MATERIAL AT THE TOP OF THE SECOND ROD AND NONCONNECTED TO OTHER RING SECTIONS AT THE BOTTOM OF THE ROD, SIGNAL INPUT CONNECTORS, ONE FOR EACH RING SECTION ON ONE SIDE OF THE ROD, CONTACTIG THE RING SECTIONS ON THAT SIDE OF THE ROD, AND SIGNAL OUTPUT CONNECTORS SIMILARLY CONTACTING THE RING SECTIONS ON THE OPPOSITE SIDE OF THE SECOND ROD. 